A retrospective cohort study was set up to evaluate the effectiveness of conservative and radical surgery for tubal pregnancy towards subsequent fertility. Consecutive patients undergoing conservative or radical surgery for tubal pregnancy between January 1990 and August 1993 in two university hospitals were included in the study. Outcome measures were spontaneous intrauterine pregnancy (IUP) and repeat ectopic pregnancy (EP). Of the 135 patients analysed, 56 underwent conservative surgery and 79 underwent radical surgery. Patients treated with conservative surgery achieved a higher 3-year cumulative pregnancy rate than those treated radically (P < 0.001, log-rank test). In patients treated conservatively, there was only one spontaneous IUP in the period between 18 months and 3 years after the tubal pregnancy. In contrast, patients treated radically continued to conceive in this period. Multivariate analysis showed a fecundity rate ratio (FRR) of 1.9 [95% confidence interval (CI): 0.91 to 3.8] for IUP after conservative surgery in the first 18 months of follow-up. In patients with a history of bilateral tubal disease the FRR was 3.1 (95% CI: 0.76 to 12), whereas in patients without a history of bilateral tubal disease the FRR was 1.4 (95% CI: 0.13 to 16). The FRR for repeat EP was 2.4 (95% CI: 0.57 to 11). Our data indicate a beneficial effect of conservative surgery towards subsequent fertility that was not, however, statistically significant in the multivariate analysis. In view of these inconclusive data and the importance of this major health problem, randomized studies are required to assess whether conservative surgery really improves the fertility prospects of patients with tubal pregnancy.

To improve the reliability and design of body armor, it is imperative to understand the failure modes and the degradation rates of the materials used in armor. Despite the best efforts of manufacturers, some vulnerability of armor materials to aging due to hydrolytic or oxidative environments is expected and may result in the degradation of material properties such as tensile strength. In this work, p-aramid yarns from two manufacturers were exposed to environmental conditions of various fixed temperature and humidity combinations. The maximum temperature and humidity condition was 70℃ and 76% relative humidity (RH). Tensile tests were performed on specimens extracted at several different times over the course of at least 1 year to determine the change in ultimate tensile strength and failure strain as a function of time, temperature, and humidity. Molecular spectroscopy was used to investigate any chemical changes as a result of the aging. The p-aramid materials were found to be generally resistant to degradation at most conditions, showing changes of less than 10% only at the highest temperature and humidity conditions.

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